What a tremendous change the past week! Take a look at high temperatures in Portland. 100s to 90s to 80s to 70s. Today we just barely made it to 70, which means we spent the whole day in the 60s. This weekend was the coolest we’ve seen in over two months.
I had a few days off last week, but working this weekend. I’ve had plenty of time to get up to speed and here’s what I’m seeing:
- We had our usual two month period of guaranteed warm/dry/sunny weather, but it was a bit early… June 15th to August 15th.
- The heat of summer is gone, and there’s no sign it’s coming back. Endless days of sunshine are done for this year. Sure, we should have plenty of warm/dry weather ahead, but expect marine air to flood inland at times too. Just like this weekend, we will have cloudy or mostly cloudy & cool days mixed in.
- We can still get up to 90 for about another month, but no model is projecting that for Portland through the rest of the month. We’re just 10 days away from September.
- I don’t see a soaking rain, or even widespread showers, for the next week
With 9 days left in “meteorological summer”, we’re still on track for the hottest summer on record. That’s both in Portland and Salem, but it’s going to be close with this recent cooldown. It may end up the 2nd hottest. Regardless, both cities DID experience the warmest 2-month period on record from mid-June to mid-August.
One surprise, and a mild forecast bust, was the heavier than expected showers today. Many areas picked up measurable rain, and .05-.10″ was not uncommon. Almost all of it was central/east metro
That makes August 22nd the 2nd day with measurable rain this month at PDX.
WHY A COOL END TO AUGUST?
For at least half the time, we’ll be under weak upper-level “troughing” or a dip in the jet stream through the end of the month. Right now a chilly system is passing by to the north in British Columbia; excellent news with all the fires up there. Here’s the Canadian model’s representation of the current setup. Cool showers up north plus lots of cool northwesterly flow coming down the B.C. coastline into Oregon/Washington
That moves east, we warm up a bit tomorrow, then quite a bit Tuesday/Wednesday. But Wednesday night another “ripple” is moving by, pushing lots of clouds inland. We’ll likely see some drizzle again Thursday morning, and some models even produce real showers Wednesday night and Thursday A.M.
By Saturday, a warm ridge is developing to our west (zig-zag line)… that’s sunnier, warmer, and back to “summer weather”. NEXT WEEKEND LOOKS SIGNIFICANTLY WARMER/SUNNIER THAN WHAT WE JUST EXPERIENCED
But just four days later, another cool trough is approaching. This is Wednesday, September 1st
What about rain? As of now, there’s no sign of a significant cool/wet spell. The ECMWF ensemble forecast for the next two weeks doesn’t show that either. Although there could be drips/showers here and there (possibly Thursday/Friday).
SUMMER ISN’T OVER, but if you want lots of hot weather, that’s not happening in the next 10 days.
This is EXCELLENT news! The last outbreak of lightning was back in the first few days of the month, and I don’t see any ahead. It appears we’ve only had one large (over 1,000 acre) fire develop in the past two weeks. That is the Fox Complex near Lakeview.
- Cooler plus higher humidity with occasional onshore pushes means less chance for huge fire starts, plus existing fires grow slowly
- Westerly flow will continue send smoke east of the Cascades most of the time the next 10 days
- I don’t see a setup where we get significant smoke west of the mountains over the next week and beyond
- This weather pattern does not produce the dangerous easterly wind with its low humidity and high temps
The largest fires (or complexes) burning right now in Oregon
It’s good that we don’t have any sort of hot easterly wind event in sight…6 of those fires are burning on the west slopes of the Cascades!
I’ve said for years that what the weather does DURING fire season is far more important than the lead up in the spring. Remember we had our driest spring on record and most of Oregon is in severe drought. BUT, if we keep lightning away, humans don’t start fires, and we get occasional cooldowns/showers, we can make it through the rest of the season…fingers crossed
Chief Meteorologist Mark Nelsen
Does anyone have any insight as to why this high pressure off the coast is so strong. I literally doesn’t make sense. It seems like after an extremely dry spring and very hot summer the pendulum should swing in the other direction. It seems like in the past if we had all these low pressure systems running into it it would have weakend it and we would have lots of damp cool weather but I really feel these times are different and something is driving this high pressure system that a la Nina or any other atmospheric index won’t be able to completely overcome to give us a wetter cooler winter as in the past. Strange, bizarre, apocalyptic times we live in
The La Nina hasn’t really kicked in yet, and its still August. Not really sure what you are talking about as this is pretty typical weather for this time of year.
The warm blob might be the reason for that strong stubborn ridge.
Hurricane Ida has made landfall in Louisiana as a strong Category 4, with sustained winds of 150, gusting to 175.
Based on satellite imagery, Ida looks as strong now as it did at landfall, which occurred several hours ago.
Brown water effect.
That whole lower part of Louisiana is marsh/swamp/bayou, filled with stagnant water that’s warmer than the ocean just to the South. It continued feeding energy and moisture into the storm, countering the effect of the terrain weakening the storm. The net product was that the storm stayed at or above Cat 2 until after Midnight (local) last night. Incredible!
Looks like models are back to their Spring pattern of flip-flopping between hot/cold and rain/no-rain. That high pressure in the ocean just does not want to go away.
Models are showing back to back storm systems hammering on it (or at least attempting) to bring us some cooler weather. Without the literally back to back storms to fight with that high pressure, we’d probably be experiencing 80+ or even 90+ degree days well into mid-September. Conversely if the ridging wasn’t there, we’d be drenched in fall rains by now. Strange times.
Yeah todays 12z gfs looked better than recent runs in the 10-14 day range (if you like cooler weather).
This isn’t really strange though. Sept is often very erratic in temperature swings.
That Pacific high does seem stronger then usual which been the case this summer with record heat so I wouldn’t be surprised if this dry pattern continues going into the fall at lest.
I was watching Mark on TV a couple of days ago and he said this is typical for late August/going into September. We will get some warm temps then cooler temps/rain then no rain. I was looking at the GFS this morning and noticed the Jet being active. I also saw a big cool air mass over the Eastern most part of Russia (temps were below 32 degrees).
I’ll say it right now, I believe we will start seeing a active pattern soon just because on how the Jet is starting to act. That’s why the High pressure systems haven’t been staying around much now. They are being pushed out of the way from the Jetstream. Its not really strong right now but it’s getting there. 🙂
The birds are flying south for the winter via radar.
Looks like the first half of September is looking warm and dry based of the latest models and cpc after a brief brush with fall this past week, the fall rains will be here soon enough.
And hopefully lots of them!
How sure are you that fall rains will be here soon? I wouldn’t be surprised if we didn’t have meaningful widespread rain until mid-October. Maybe we can have an 8 month summer if we’re lucky.
Unfortunately, when we get warm or hot weather in September and early October its usually associated with a dry east wind.
Speaking of which the 12z gfs has seattle right at 100 on the 10th, gotta be an outlier.
Not happening lol.
0.17 inches of light rain here yesterday afternoon and a few leftover showers this morning. Feels like summer is over, but it’s just a feeling- it can get warm again.
All I have to do is look out my window and see summer is indeed over in Portland. Maybe not for south, central and eastern Oregon but it’s definitely done here in the northern valley.
Look out your window tomorrow afternoon when it comes back then.
Sure it might be sunny, warm… definitely not. The marine layer is doing it’s thing and has definitely decided summer is over for those of us in Portland. I don’t care what anyone says, the marine layer ruins all the nice days in Portland, that is a fact.
Dude 90s are still entirely possible into late September.
New post from cliff mass he mention were ending summer much cooler then normal, I just wonder how rare it is to have a pattern like this in late August it doesn’t happen very often at all, I hate to think this could be are fall now then warmer then normal in true fall.
I see some people are talking about the long range forecast were it shows 90+ degree weather on the GFS and CFS model. I don’t know how many times I have seen something that far out and was hoping it will happen and when those dates came up, it didn’t happen. The calculations that far out is probably around 20 to 30 percent that it will happen. The atmosphere is a very complex thing and a lot can change between now and then.
I’m not saying it can’t happen but I wouldn’t hold my breath that it will happen. I have been on this blog for a very long time and been living in the Portland area all my life (50+ years) and learned the hard way of jumping the gun on what the models are saying 10+ days out. I would wait until it’s around 7 days out to say it’s going to happen. As some would say, “it’s out in la la land.”
I’ve been seeing people say “summer it’s over.” It’s not over by a long shot. I’ve seen some heatwaves in September. I was born on September 6th and my mom (rest in peace) told me the year I was born, there was a heatwave so summer isn’t over just yet.
On a weather note, I am noticing the Jet Stream is starting to get stronger and more active which could mean we could start seeing more active weather in the future. We’ll see how that plays out.
On that note, have a good evening 🙂
Lot of folks and meteorologists prematurely declaring summer weather is over. There’s plenty of 80+ degree days left and GFS has some 90+ brewing towards the middle of September, so I wouldn’t jump to that conclusion quite yet no matter how desperate we are to dive into Fall weather.
Yeah, the cfs model been showing a warm up by mid September for over two weeks, the gfs is finally latching on now, I’m the only one that gives the cfs model credit it has it’s problems but it’s more accurate then most people realize, hopefully there won’t be a strong east wind with this heat event.
Hopefully there will be no heat event altogether. Very far from certain at this point.
Hmmm, yeah Tim I’ll give you that the cfs actually often nails trends, including this last mid-February thing. It’s not prediction of events at all, just a better chance of this or a better chance of that.
Salem’s rainless streak ended at 71 days. I hope this makes Natasha Stenbock happy. She certainly seems to harp on it when we get .01 of precipitation. Like it’s a big deal. I find her forecasts seem to have a cool bias and precipitation bias when compared to the other tv mets. Anyway we should be up around 90 this weekend. No September that I’m aware of in at least the last 60 years has been absent at least 1 day over 90. I don’t see that happening this year either. Nevertheless Summer is winding down. Peace.
2018 wants a word with you (August 28th was the last day then).
I am using the Salem dates instead of Portland since that appears to be where you are. That being said, it is still uncommon with a seeming return period once every 4 years or so.
Model’s showing some rain around 8th and 9th of September time frame…it has been showing this for several run’s now…I hope it holds together…consolidated jet and cold front into the NW…hopefully it stays on the Model’s.
00z gfs holds it off until the 11th now and a bit weaker too, seems to be the situation as we get closer to the event or just completely dissipates, the models have been over performing with the rain for months.
You are correct, it changed again… I have a feeling were back to three days out for any reliability on the models…the high pressure off the coast just seems to hold on…this could affect our fall and winter if it doesn’t go away…
We’re heading into the last 7 days of August- that’s often a time when the weather can shift dramatically in the PNW. Just a quick example; 3 years ago on August 25,2018 after weeks of dry, very warm weather, my location saw low overcast skies and steady light rain and drizzle. The maximum temperature was 57.9F. That’s only one,rather modest case. I’ve seen days with over 2 inches of rain.
Then after that, it often gets warm and dry again.
Summer isn’t over, I repeat summer isn’t over. Are you trying to convince us or yourself Mark. We all know you hate summer gloom and want the heat and sunshine to last as long as possible no matter how many acres of Oregon burn down.
Some haze and surface level smoke seems to have crept in. Air quality is in the moderate category as well. Wondering if we would’ve hit 90 without it.
Our consecutive string of rainless days has reached 70. Amazing how it has been so hot and dry this Summer. But thanks to global warming next Summer could be just as warm. Peace.
Low of 43 at my place yesterday morning, down to 48 this morning. Some of the things in my garden aren’t going to appreciate that…
The 12z gfs is showing some big time troughing in the last 100 hours. If models keep trending this way the next week or so, summer may very well be over.
Would you explain what that means in Layman’s terms? I’m still learning weather/lingo terms, thank you!
18z says not so fast. That ridging over the Pacific just seems to keep bouncing up and down, not really going away.
Looks like we have already entered at least moderate La Nina temp anomalies, We will wait and see what its going to be…. Also mark you normally make a post this time of year about farmers almanac and old farmers almanac, they are both out now! But their forecasts is just like throwing a dart at a board kind of random!
My info from studying repeating La Nina’s:
2016-2017 and 2017-2018 repeating La Nina, 2016-2017 very above average snow very above average rain very below average temp, 2017-2018 a less extreme 2016-2017
2010-2011 and 2011-2012 repeating La Nina, 2010-2011 above average snow and rain very snow mountains and a bit below average temps, 2011-2012 below average temps very above average rain, a bit above average snow
2007-2008 and 2008-2009 repeating La Nina, 2007-2008 very cold snowy and rain, 2008-2009 EXTREMELY cold snowy and rainy
1998-1999 1999-2000 2001-2002 three peat La Nina, 1998-1999 very snowy and rainy and colder, 1999-2000 a bit more extreme then the previous year, 2000-2001 a typical La Nina
1983-1984 and 1985-1986 repeating La Nina, 1983-1984 extremely snowy and cold 1984-1985 even more extreme
1973-1974 1974-1975 1975-1976 three peat La Nina, all of them pretty extreme, 1975-1976 a bit more extreme than the previous years
This point on is when my data is less accurate, but it’s still accurate
1970-1971 and 1971-1972 repeating La Nina, 1970-1971 above average snow and rain and pretty cold, 1971-1972 more snowy the the year before, but everything else is pretty much the same.
1954-1955 and 1955-1956 repeating La Nina, 1954-1955 VERY cold and snowy, 1955-1956 VERY EXTREME COLD And extremely snowy
From what i looked into, my conclusion is this La Nina will be at least as moderate as last year, at this rate from the temperature anomalies it will actually be more extreme!
Correct me if I am wrong on anything Please!
There has been rapid warming in region 1+2 almost looks like el Nino is forming but cooling in region 3.4, odd.
El Nino is forming in a way but thats typical when cold water comes out, Probably won’t happen.
It will be interesting to see how we transition into the forecast La Nina pattern that the NOAA CPC has had in the offering for at least a few months now. I believe we are under a watch for that pattern I think the last I saw on the CPC website.
I sure wish the dry weather would end. The lawn as well as some of the plants here in Southeast Tacoma are getting pretty crispy dry. I don’t think the lawn here has grown even micro inches in over a month around here either.
I’ve consistently watered my front lawn – which is north facing – all summer long. It has not grown a millimeter since at least before the record heatwave in June. My poor lawnmower will probably need to get the carb cleaned for the second time this year due to lack of use.
Funny thing happened this morning. I woke up before my alarm went off (4am) and all of a sudden, the furnace kicked on…lol. I haven’t touched the thermostat for a few months because it’s been so warm. I went downstairs and saw it was set for 66 degrees. It hasn’t been that temp for a long time inside the house…lol.
I was just looking at the 18Z GFS and the 12Z Euro and they look a lot similar, I actually think we probably won’t see any extreme warm weather for awhile. What I do see in both models is the flow is coming from the West to NW which we probably just see average highs for this time of year for probably 8 to 10 days.
I haven’t really been watching the models lately because of work but I’ll try to look at the models more often in the future.
Looks like PDX tied it’s record low this morning
So nice to get some rain Friday night/Saturday morning. 47 degrees this morning. Starting to feel more Fall like that is for sure. Would be happy to see a bit more rain to lessen the fire danger. Otherwise this weather is great!
Yes, Summer is over. The marine layer seems to be winning this fight and all the forecasts are the big losers.
A false fall now the heat may be back in September although not as extreme as this summer, cpc does have us below norm temps and below norm precip in the 8-14 outlook, like I said earlier a cool/dry fall is most likely great for raking leaves.
The 90+ degree weather can happen into the first week of October. The fire isn’t out of the woods yet
Does somebody have a thermometer I can borrow? I think mine is broken. It shows 46 outside.
Thanks for keeping us Corbettites ? up to date on the weather this summer. I for one appreciate it am proud to call you “our weatherman”.
On Sun, Aug 22, 2021 at 9:28 PM FOX 12 Weather Blog wrote:
> Mark Nelsen posted: ” 9:30pm Sunday What a tremendous change the past > week! Take a look at high temperatures in Portland. 100s to 90s to 80s to > 70s. Today we just barely made it to 70, which means we spent the whole day > in the 60s. This weekend was the coolest we’ve se” >
What will REALLY be cool is…….(creepy smile) when you apologize for Master Kogah’s death………..IN PERSON! (Insert creepy piano note here and disguise wears off as a male Yiga with a deep laugh appears)
HA HA HA HA HA HA! (Brings out WindCleaver and battle theme plays)
Fooled you! You thought I was an innocent NPC.
Hi Kyle! Dis you miss a dose of your meds yesterday?
You see an NPC crying in Corbett: “Ohhhh Master Kogha’s SO dreamy!” she says.
A: Master Kogha?
B: Master Kogha has a dumb belly!
Maybe a cool/dry fall on the way I would be fine with that 2013 was are last dry\cool fall after a wet September here in western wa.
Now this is the summer weather I’ve been yearning for! Nice balance of mild and hot days with the occasional spotty rain. As it should be!
We just need to get this pandemic under control and we’ll be in decent shape 🙏
“We just need to get this pandemic under control and we’ll be in decent shape 🙏”
I’ll just leave it at this: Be careful what you wish and vote for as certain groups have some very ahem colorful ways of wanting to handle it similar to scenarios in the past.
Don’t want my post get censored. He he.